Tetramicra brevifilum (Matthews & Matthews, 1980) (Microsporida: Tetramicriidae) in a new fish host, Lophius budegassa (Spinola, 1807) in Spain.

Tetramicra brevifilum, a microsporidian parasite of Scophthalmus maximus, was found in Lophius budegassa for the first time. This parasite was detected in 5 of 199 hosts captured in the coastal waters of Barcelona (Northwest Mediterranean), which enlarges the geographic distribution of this microsporidian. Affected fish did not show any external sign of disease, and cysts of T. brevifilum were found associated with the body musculature but were easily differentiated from those of Spraguea lophii, another microsporidian present in this host. A case of simultaneous infection by both T. brevifilum and S. lophii was found.

Longevity and effects of temperature on the viability and polar-tube extrusion of spores of Glugea stephani, a microsporidian parasite of commercial flatfish.

Food contamination with respect to microsporidiosis in humans (associated with acquired immunodeficiency syndrome) and in marine fish farming deserves particular attention. For the first time, a study on the longevity and resistance to both heat and freezing of the spores of a vertebrate microsporidian, Glugea stephani, parasitizing a commercial flatfish was carried out. As judged on the basis of determinations of the extrusion rate, the resistance of the spores to temperature stress was remarkable. The extrusion rate, which can be directly related to infectivity, was always lower than the viability (membrane integrity). It should be pointed out that neither heat (60 degrees C for 30 min) nor freezing (-19 degrees C for 24 h) caused a complete reduction in the extrusion rate or viability. Consequently, the ingestion of poorly cooked or raw fish (even if previously frozen) represents a danger for aquaculture and, probably, for immunodepressed patients.